Abstract

After discussing the design principles of soft X-ray interferometers, we present in some details the implementation and recent results of an experiment currently developed at Orsay, to measure the dispersion of the carbon refractive index, near the K-edge. A particular stress will be given to the moiré-based detection system, which provides a quick, nearly “real-time“ measurement of the sample optical thickness.

More generally, as interferometric techniques provide access to the optical phase of X-ray wavefronts, they should bring a powerful new toolbox for doing physics with soft X-rays. A short overview on some interferometric experiments, in preparation or already attempted, will be given.